The unqualified flaw detection for thick ASTM A387 Grade 11 Class 2 vessel steel plate

ASTM A387 Grade 11 Class 2 vessel steel plate is very strict in production and inspection because of its special uses. A387 Grade 11 Class 2 steel plates usually need ultrasonic flaw detection to detect the quality defects inside the ASTM A387 Grade 11 Class 2 steel plate.

The internal structure of thick gauge ASTM A387 Grade 11 Class 2 vessel steel plate was analyzed by metallographic and scanning electron microscopy.
The results show that the micro-crack caused by inclusion is the main reason for the defect detection failure of ASTM A387 Grade 11 Class 2 vessel steel plate.

The measures such as dynamic soft reduction technology, steel billet, steel plate stacking and 48h slow cooling were put forward to reduce the superheat of molten steel. These methods can effectively improve the qualification rate of ASTM A387 Grade 11 Class 2 vessel steel plate flaw detection.